1925] Setchell-Gardner: Melanophyceae 565 



Desmarestia intermedia has usually passed for D. acideata, true 

 representatives of which do not seem to occur on our coast. D. acideata 

 is characterized, at least in typical forms, by having its shorter and 

 even longer branches margined by short branches of limited growth, 

 asuming the form of spines. D. intermedia, however seldom has what 

 appear to be genuine aculeae, i.e., short rigid spine-like branches of 

 very limited growth such as are characteristic of D. aculeae and D. 

 latifrons, usually there being little, if any, appearance of this sort. One 

 characteristic of D. intermedia is the fasciculate branching below. The 

 groups of branches springing from one point are subopposite, i.e., arise 

 near one another, but one bunch is inserted higher on the axis whence 

 both arise and not exactly on the opposite side. The plants we have 

 assigned to this species vary from fairly broad (type) to medium (var. 

 fuscescens P. and R., lac. cit.) and on to the most slender and almost 

 terete forms (var. teretifolia P. and R., lac. cit.). 



Postels and Ruprecht (lac. cit.) seem to feel certain that the nomen 

 nudum of Mertens, Fucus pseudoaculeatus, refers to their plant, hav- 

 ing probably examined a specimen, but they consider the other three 

 quotations, viz., Sporochnus medius Ag., Trmitaria confervaides Bory, 

 and Desmarestia media Grev., as dubious. The first and the last refer, 

 in our opinion, to what we call Desmarestia media. The middle plant 

 is presumably another species, having been assigned to a plant of 

 the southern hemisphere. 



Section 3. Herbaceae 



Desmarestia, subgenus Eudesmarestia, De-Toni (loc. cit.), in part. 



Fronds ligulate to broadly membranaceous or foliaceous; branch- 

 ing abundant to very sparse or none, opposite or subopposite. 



De-Toni, Syll. Alg., vol. 3, 1895, p. 457. 



There is a very considerable variation in length, width, and branch- 

 ing in our west American plants of the Herbaceae and there are very 

 considerable difficulties in the way of classifying them either as dis- 

 tinct species or as varieties. Miss Vinnie Pease (1917 and 1920) has 

 made an effort in this direction and we have considered her account 

 and the opinions she has expressed therein, very carefully. As a 

 result of our study of the literature and of the specimens, we have 

 decided to mark off the more striking plants of our coast as more or 

 less distinct species. 



